Implement type inference of static invocations.

pkg/front_end/testcases/inference/downwards_inference_on_function_arguments_infer_downwards.dart.strong.expect

Index: pkg/front_end/testcases/inference/downwards_inference_on_function_arguments_infer_downwards.dart.strong.expect
diff --git a/pkg/front_end/testcases/inference/downwards_inference_on_function_arguments_infer_downwards.dart.strong.expect b/pkg/front_end/testcases/inference/downwards_inference_on_function_arguments_infer_downwards.dart.strong.expect
new file mode 100644
index 0000000000000000000000000000000000000000..e6642f5ce3706d052012aa86514f884a087476e3
--- /dev/null
+++ b/pkg/front_end/testcases/inference/downwards_inference_on_function_arguments_infer_downwards.dart.strong.expect
@@ -0,0 +1,31 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+static method f0(core::List<core::int> a) → void {}
+static method f1({core::List<core::int> a = null}) → void {}
+static method f2(core::Iterable<core::int> a) → void {}
+static method f3(core::Iterable<core::Iterable<core::int>> a) → void {}
+static method f4({core::Iterable<core::Iterable<core::int>> a = null}) → void {}
+static method main() → void {
+  self::f0(<core::int>[]);
+  self::f0(<core::int>[3]);
+  self::f0(<core::int>["hello"]);
+  self::f0(<core::int>["hello", 3]);
+  self::f1(a: <core::int>[]);
+  self::f1(a: <core::int>[3]);
+  self::f1(a: <core::int>["hello"]);
+  self::f1(a: <core::int>["hello", 3]);
+  self::f2(<core::int>[]);
+  self::f2(<core::int>[3]);
+  self::f2(<core::int>["hello"]);
+  self::f2(<core::int>["hello", 3]);
+  self::f3(<core::Iterable<core::int>>[]);
+  self::f3(<core::Iterable<core::int>>[<core::int>[3]]);
+  self::f3(<core::Iterable<core::int>>[<core::int>["hello"]]);
+  self::f3(<core::Iterable<core::int>>[<core::int>["hello"], <core::int>[3]]);
+  self::f4(a: <core::Iterable<core::int>>[]);
+  self::f4(a: <core::Iterable<core::int>>[<core::int>[3]]);
+  self::f4(a: <core::Iterable<core::int>>[<core::int>["hello"]]);
+  self::f4(a: <core::Iterable<core::int>>[<core::int>["hello"], <core::int>[3]]);
+}